Just found a couple of typos in banner_manage.php (also edited it to have double quotes instead of single in the output code).
Find...
PHP Code:
$code = "<a target='blank' href='$forumurl/click.php?bannerid=$bannerid'><img border='0' width='$width' heigth='$height' alt='$alt' src='$forumurl/view.php?bannerid=$bannerid'></a>";
Change to...
PHP Code:
$code = "<a href=\"$forumurl/click.php?bannerid=$bannerid\" target=\"_blank\"><img src=\"$forumurl/view.php?bannerid=$bannerid\" border=\"0\" width=\"$width\" height=\"$height\" alt=\"$alt\"></a>";